Signals and slots in flow allows users to handle or execute any function based on an event. When an event is triggered a signal is emitted by using signal method and this is then handled by the slots listening to this signal. A slot can be any method defined in Flow and user can execute any code in the slot depending on his/her requirement Defining and Using Signals To define a signal, create a method which starts with emit and annotate it with a Signal annotation. Whatever parameter are defined in the signal will be handed over to any slots listening to that signal. The Signal...